line_send_message · UnClick MCP: Risk & Policy

WHAT IT DOES

What line_send_message does on UnClick

AI agents use line_send_message to create or update resources in UnClick — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your UnClick environment.

PARAMETERS

Parameter	Type	Required	Description
`to`	string	Yes	User ID, group ID, or room ID
`message`	string	Yes
`channel_access_token`	string	Yes

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why line_send_message needs a policy

This tool creates and transmits messages, which is a write operation that modifies state in an external system (LINE messaging platform). It is not destructive (messages are not irreversibly deleted), not execute (no code/shell commands), not financial.

From the tool's definition Tool description states 'Send a text message to a LINE user, group, or room' — the verb 'send' indicates a message transmission action that creates and delivers new data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

line_send_message Rate-limited

line_send_message stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "line_send_message": {
      "limits": [
        {
          "counter": "line_send_message_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches UnClick, so you can run agents against it safely.

FAQ

Questions about line_send_message

What does the line_send_message tool do? +

Send a text message to a LINE user, group, or room. It is categorised as a Write tool in the UnClick MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does line_send_message accept? +

line_send_message accepts 3 parameters: to, message, channel_access_token. Required: to, message, channel_access_token. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on line_send_message? +

Register the UnClick MCP server in PolicyLayer and add a rule for line_send_message: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches UnClick. Nothing to install.

What risk level is line_send_message? +

line_send_message is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit line_send_message? +

Yes. Add a rate_limit block to the line_send_message rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block line_send_message completely? +

Set action: deny in the PolicyLayer policy for line_send_message. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides line_send_message? +

line_send_message is provided by the UnClick MCP server (@unclick/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.